objective-c随机数+日期格式显示一例

在原来的代码上有修改，主要为：

1. 将准备随机数方法放到了init中，这样不用手动调用了
2. setWeek方法已经过时，使用的是setWeekOfYear方法

在此放一份以备以后查找：

le.h

////  LotteryEntry.h//  lottery////  Created by kinds on 15/6/25.//  Copyright (c) 2015年 hopy. All rights reserved.//#import <Foundation/Foundation.h>@interface LotteryEntry : NSObject{    NSDate *entry_date;    int first_number;    int second_number;}-(void)prepareRandomNumbers;-(void)setEntryDate:(NSDate*)date;-(NSDate *)entryDate;-(int)firstNumber;-(int)secondNumber;@end

le.m

////  LotteryEntry.m//  lottery////  Created by kinds on 15/6/25.//  Copyright (c) 2015年 hopy. All rights reserved.//#import "LotteryEntry.h"@implementation LotteryEntry-(id)init{    self = [super init];    if(self){        [self prepareRandomNumbers];    }    return self;}-(void)prepareRandomNumbers{    first_number = ((int)random()%100) + 1;    second_number = ((int)random()%100) + 1;}-(void)setEntryDate:(NSDate *)date{    entry_date = date;}-(NSDate*)entryDate{    return entry_date;}-(int)firstNumber{    return first_number;}-(int)secondNumber{    return second_number;}-(NSString *)description{    NSDateFormatter *df = [NSDateFormatter new];    [df setTimeStyle:NSDateFormatterShortStyle];    [df setDateStyle:NSDateFormatterMediumStyle];    return [[NSString alloc]initWithFormat:@"%@ = %d and %d",            [df stringFromDate:entry_date],first_number,second_number];}@end

main.m

////  main.m//  lottery////  Created by kinds on 15/6/24.//  Copyright (c) 2015年 hopy. All rights reserved.//#import <Foundation/Foundation.h>#import "LotteryEntry.h"int main(int argc, const char * argv[]) {    @autoreleasepool {        NSDate *now = [NSDate new];        NSCalendar *cal = [NSCalendar currentCalendar];        NSDateComponents *to_week = [NSDateComponents new];        srandom((unsigned)time(NULL));        NSMutableArray *mary = [NSMutableArray new];        for(int i = 0;i<10;i++){            [to_week setWeekOfYear:i];            NSDate *from_now = [cal dateByAddingComponents:to_week toDate:now                                                   options:0];            LotteryEntry *le = [LotteryEntry new];            //[le prepareRandomNumbers];            [le setEntryDate:from_now];            [mary addObject:le];        }        for(LotteryEntry *le in mary)            NSLog(@"%@",le);    }    return 0;}